Epidemiologic data on the health effects of disasters such as terrorist incidents is essential to help guide relief and recovery efforts. No large-scale, comprehensive, population- based analysis of the effects of the September 11, 2001 terrorist attacks on the incidence, prevalence, patterns and trends of substance abuse has been conducted. This proposed analysis of outpatient and emergency department Medicaid data offers a valuable opportunity to help describe and analyze how epidemiologic measurement and methodology utilizing large, administratively collected health data sets can be utilized in the context of dramatic changes in the physical, social and economic environment to assess drug abuse following terrorism, man-made and natural disasters. The statistical analyses will include methodology to address issues of correlated data, spatial relationships, and the inclusion of geographic and built environment measures to help improve causal inference from non-experimental sources of data to assess the effects of the terrorist attacks. The hypothesis is that there were measurable short-term and long-term behavioral health effects among individuals exposed to the attacks on and subsequent collapse of the World Trade Center towers in New York City, that these effects were due to traumatic stress, were spatially mediated via proximity to the events, and were associated with adverse overall social, economic and public health of the affected communities. The specific aims are to (1) Review, document and synthesize the literature on the effect of mass events such as terrorism on substance abuse (2) Conduct time series analyses of patterns of drug abuse in New York City communities for the periods preceding, during and following the terrorist attacks of September 11, 2001 to determine if disruptions in social and economic environments are linked to changes drug use behavior and (3) Determine if there is evidence of a spatial association between the effects of the post-attack period and drug abuse. The project builds on initial research conducted by the principal investigator into the health effects of the terrorist attacks of September 11, 2001 on the communities of New York. It will utilize methods of meta-analysis, Poisson and logistic regression, interrupted and dynamic time series analyses and Bayesian approaches to hierarchical spatial modeling. Results will lead to recommendations for emergency management practitioners and policy makers in preparing and mobilizing their communities for disasters or terrorist events, as well as for behavioral health researchers and practitioners in identifying risk, vulnerability, protective and resiliency factors when planning community-wide health interventions following terrorist attacks and natural disasters. [unreadable] [unreadable] [unreadable]